package test3_25.demo16;
/*
定义一个方法，将str所指字符串的正序和反序进行连接,例如 “ok”->“okko”
 */
public class Homework14_15 {

    public static String concat(String str){
        StringBuilder sb = new StringBuilder(str);
        String str1 = sb.reverse().toString();
        return str+""+str1;

    }

    public static void main(String[] args) {
        System.out.println(Homework14_15.concat("ok"));
    }
}
